Mechanical movement



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Patented Dec. 21,1897.

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- W. A. PITT.

- MECHANICAL MOVEMENT. No. 595,732. Patented Dec. 21, 1897.

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T N E @m .W P. .L AM m WA H 0 E m d 0 M 0 vJ No. 595,732 Patented Dec. .21, 1897.

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WITNESSES:

NI-TED STATES PATENT FFICE.

WVILLIAM A. PITT, OF MANHASSET, NEW YORK.

M ECHANICAL MOVEM ENT.

SPECIFICATION forming part of Letters Patent No. 595,732, dated December 21, 1897. Application filed January 18, 1897. Serial N0. '619,037. (No model.)

To aZZ whom it may concern:

Be it known that 1, WILLIAM A. PITT, a citizen of the United States, residing at Manhasset, Queens county, New York, have invented certain new and useful Improvements in Mechanical Movements, of which the following is a Specification.

This invention relates to a mechanical movement for converting reciprocating into rotary motion; and the leading object is to obviate the difficulty of passing centers. In

the case of two reciprocating motorsacting on cranks set oppositely on a common shaft the cranks are never in my device on the center at the same time, and in the case of a single motor acting on a crank the motor is made to act through considerably more than one-half the travel of the crank, whereby the fly-wheel is required to carry the shaft through less than half the rotation.

In the accompanying drawings, which illustrate several embodiments of the invention, Figure 1 is a side elevation showing an application of the device wherein two reciprocating engines'act on two cranks set oppositely on a common shaft;- and Fig. 1 is a cross-section on line 00 of Fig. 1, showing the construction. Fig. 2 is a plan of the device as seen in Fig. 1. Figs. 3, 4, and 5 are some- What fragmentary views illustrating different ways of applying the power to the rolling f ulcrum-wheel. Fig. 6 is a side elevation illus-' trating the conversion of reciprocating pedal motion into rotary motion according to my invention. Fig. 7 is a fragmentary view illustrating the application of a treadle to a single crank according to my invention.

Referring first to Figs. 1, 1 and 2, A represents a shaft to be rotated. This shaft has bearings in two frames B 13 and bears at each end a crank, these being lettered O and O The cranks are set oppositely on the shaft, on which are shown also a fiy-wheel D and driving-pulley E. To the respective cranks are coupled suitable connecting-rods F and F these rods being coupled, respectively, at their other lower ends to arms G and G fixed to toothed wheels H and IF, which gear at their upper sides with fixed racks I and I on the respective frames B and l3 and at their lower sides with sliding racks J and J mounted in suitable guides in the respective frames. K and K represent two ordinary reciprocating-engine cylinders, which have piston-rods L and L which are coupled to the respective racks J and J Fig. 1 illustrates the preferred mode of constructing and mounting the toothed wheels H and H in the respective frames B and B The wheel H has a journal h, which rotates in a block W, that is adapted to slide to and fro in a slot 5 in the frame B, parallel with the racks I and J, a nut and washer on the end of the journal h serving to hold the parts in place. On the outer faces of the respective Wheels H and H are fixed guidingdisks M and M which take over on the outer sides of the racks, as clearly shown.

As to the proportions of the several parts I will say that thp arm G will be of twice the length of the crank C and will move through about one-fourth of a rotation while the crank is moving through a half-rotation. As shown in Fig. 1, the connecting-rod F is aboutv five times the length of the crank O, and the diameter of the wheel H is such that in rolling on the rack I through a quarter-rotation the center of the wheel will travel a distance along the slot 1) equal to the length of the arm G. The travel of the piston in the cylinder of engine K will equal the distance traveled by the center of the Wheel H, plus onefourth the circumference of the said wheel, measured on the pitch-circle. The operation is simple. Alternate reciprocation of the sliding racks J and J X by the engines K and K roll the-fulcrum-wheels H and H along the fixed racks I and I and swing the arms G and G through a quarter rotation. These movements of the arms act through the connecting-rods F and F and cranks O and O to rotate the shaft A.

It will be noted that when one crank, as (J in Fig. 1, is on the center, the engine K being at the end of its instroke and the engine K nearly at the end of its outstroke, the upper crank O is oblique .to the connecting-rod F so that a downward pull on said rod may act with a good crank leverage for carrying the other crank off from its center. The connecting-rods F and F are never parallel when the engines are at the ends of their strokes complete the rotation.

or in the relative positions described, and hence there can be no dead-center. Then the crank C is passing its center, the engine K will he at the end of its outstroke, and when the parts have reached the position seen in Fig. l the said engine will have just started on its back stroke, so the engines do not reach the ends of their strokes at exactly the same time, but nearly so.

I have not deemed it necessary to illustrate the engines K and K in full. It will suffice to say that they may be of the ordinary kind, with the valves operated from cams or eccentries on the shaft A and so set as to shift at the proper times.

For simplicity I have shown the racks I and J as gearing with teeth on opposite sides of the same toothed wheel; but the same result in principle may be obtained by having the racks I and J gear with wheels or wheel-seg ments of different diameters, as illustrated diagrammatically in Fig. 3. In this case the larger wheel-segment H gears with the fixed rack I and the smaller wheel-segment H gears with the sliding rack J, and in this case the stroke of the engine-piston will of course be less than in the construction shown in Fig. 1.

Other means than a sliding rack may be employed for imparting a to-and-fro rolling and reciprocating movement to the wheel H along the fixed rack. For example, the piston-rod L of the engine may be coupled directly at the center of said wheel to its journals, as seen in Fig. 4., or the rod L may be coupled to an arm N on said wheel, as indicated in Fig. 5. In Fig. 6 the movement is imparted through two pedals O and O on arms on the respective wheels H and H and in Fig. 7 a treadle P is employed with a single crank C, a fly-wheel being employed to p This View illustrates the treadle acting through more than onehalf the rotation of the crank.

I may say that the term Wheel as here applied to the rocking fulcru ms II or l-I must be understood as broad enough to include a toothed segment, the teeth being employed to compel rotation as the wheel is moved to and fro in its guide in the slot 1). The axis of this wheel will always be parallel to the shaft A to be rotated. The radial arm G may be fixed integrally or in any manner to the fulcrumwheel or to the disk M, if such disk be employed. I do not consider this disk to be essential, but prefer to employ it especially where a rack J is employed. In the construction seen in Fig. 5 the piston-rodmust be jointed, as shown, in order to allow the end coupled to the arm N to move in a curve.

What is herein called the fixed rack may be any equivalent device which compels wheel. In any case it is rigidly connected with said wheel either directly or indirectly.

I may say that ordinarily the reciprocating movement of the fulcrum-wheels will be in a horizontal path, as herein shown; but the word horizontal must be understood as used herein in a descriptive sense only and not as a limiting phrase.

Having now fully and clearly described my invention and the objects to be attained by its use, I will say that I am well aware it is not new to employ a rolling cogged cross-head arranged between a fixed rack and a rack on or carried by the piston-rod of a reciprocating engine, and this I do not claim. Such a device as heretofore employed does not attain the object I seek. I am also well aware that it is not new, broadly, to employ a toothed fulcrum-wheel rolling on a stationary rack,

the piston-rod being coupled to the journals of said wheel and the crank coupled to said wheel at a point less distant from the center of the latter than the length of the crank.

'This device I do not claim, nor will it attain the object I seek to attain. In my construction the axis of the crank-shaft is parallel with but in a different plane from that of the fulcrum wheel or wheels. The arm G of the fulcrum-wheel H greatly exceeds the crank in length. Indeed it will be by preference just twice the length of the crank, as explained, whereby, as seen in Figs. 1 and 6, when one crank is on the center the other will be off the center.

Having thus described my invention, I claim- 1. The combination, with a crank-shaft, a crank thereon, and means for producing a reciprocating movement, of an intermediate mechanism for converting said reciprocating movement into rotary motion of said crankshaft, such mechanism comprising a fixed rack, a toothed fulcrum-Wheel mounted in a guide and in gear with said fixed rack, said wheel being moved to and fro in its guide by said reciprocating means, the guide for said wheel, a radial arm on said wheel and of greater length than the crank, and a connecting-rod coupling the crank on the shaft to said arm, the axis of said crank-shaft being parallel with but in a different horizontal plane from that of the fulcrum-wheel, sub stantially as set forth.

2. The combination, with a crank-shaft, a crank thereon, and means for producing a reciprocating movement, of an intermediate mechanism for converting said reciprocating movement into rotary motion of said crankshaft, such mechanism comprising a fixed rack, a guide arranged parallel with said rack, a rotatable, toothed fulcrum-wheel, in gear with said rack and mounted in said guide, said wheel being moved to and fro in the guide by said reciprocating means, a radial arm carried by said fulcrum-wheel and of substantially twice the length of the crank, and a connecting rod coupling said arm to the crank, the axis of the crank-shaft being parallel with but in a different horizontal plane from that of the f ulcrum-wheel, substantially as set forth.

3. The combination with a crankshaft and the crank thereon, of means for rotating the said shaft-,said means com'prisinga fixed rack, a guide parallel with said rack, a fulcrumwheel rotatively mounted in said guide and in gear with said rack, whereby when said Wheel is moved along its guide it is compelled to rotate, a radial arm carried by said fulcrum-wheel and of double the length of the crank on the shaft, and a connecting rod which couples the saidarm to said crank, the axis of said crank-shaft being parallel with but in a different horizontal plane from that of the fulcrum-Wheel, substantially as set forth.

4. The combination with a crank-shaft, two like cranks fixed and set oppositely thereon,

and two like reciprocating devices adapted for operation on the respective cranks, of two like intermediate converting mechanisms, one between each reciprocating device and its crank, each such converting mechanism comprising a fixed rack arranged transversely to the said crank-shaft, a fulcrum-wheel in gear with said rack and provided with an arm of substantially double the length of the said crank, anda connecting-rod coupled at one end to the crank and at the other end to the arm on the fulcrum-Wheel, the axis of said crank-shaft being parallel with but in a different plane from the axes of the fulcrumwheels, substantially as set forth.

In witness whereof I have hereunto signed my name in the presence of two subscribing witnesses.

WILLIAM A. PITT. Witnesses:

HENRY CONNETT, PETER A. Boss. 

